Daily Environmental Monitoring Summary

Thursday, December 13, 2001

The U.S. Environmental Protection Agency (EPA) and other federal, state and local agencies have collected extensive environmental monitoring data from the World Trade Center site and nearby areas in Manhattan, Brooklyn and New Jersey. Since September 11, EPA has taken samples of the air, dust, water, river sediments and drinking water and analyzed them for the presence of pollutants that might pose a health risk to response workers at the World Trade Center site and the public. The samples are evaluated against a variety of benchmarks, standards and guidelines established to protect public health under various conditions. EPA is collecting data from more than 20 fixed air monitors in and around ground zero and additional monitors in the Bronx, Brooklyn, Queens and Staten Island. The Agency is also using portable sampling equipment to collect data from a range of locations.

Results as of 5:00 p.m. on 12/13

Air: Fixed Monitors in New York:

Asbestos - EPA analyzed 43 samples taken in and around ground zero from December 9 through December 10. In addition, EPA sampled for asbestos at three additional lower Manhattan locations on December 7 and 8 for a total of 49 samples. All samples showed results less than 70 structures per square millimeter, which is the Asbestos Hazard Emergency Response Act (AHERA) standard for allowing children to re-enter school buildings after asbestos removal activities. This brings the total number of air samples collected and analyzed for lower Manhattan to 3,333, with 29 samples above the standard (27 of these were collected prior to September 30, one was collected on October 9 and the other on November 27).

Air (Asbestos) - Thirty-seven air samples collected on December 9 and 10 were analyzed for asbestos. All of these samples were below the school re-entry standard.

Air (Particulates) - EPA used portable monitors to collect samples of particulates on December 12 at the Staten Island Landfill. No significant readings reported.

Particulate Monitoring - EPA used portable monitors to collect samples on December 12 in the following locations: L (north east side of Stuyvesant High School); N (south side of Pier 25); and R (north west side of Stuyvesant High School). All readings were below the OSHA time-weighted permissible exposure limit for particulates.

VOCs - Sampling for volatile organic compounds (VOCs) was conducted on December 12 in the direct area of the debris pile at ground zero. To protect workers at the work site, EPA takes grab samples of VOCs where smoke plumes have been sighted. The results are snapshots of the levels at a moment in time. OSHA's protective standards set a permissible exposure limit (PEL) averaged over an 8-hour day. Benzene exceeded the OSHA standard at one location on the debris pile at the North Tower. Two of three samples taken at EPA's Wash Tent (West St. and Murray) and Austin Tobin Plaza showed no detectable levels of benzene.

Direct Air Readings - EPA did air monitoring in and around ground zero for a number of compounds on December 12. No significant readings were found. Low levels of carbon monoxide were detected. Correction: EPA's Dec. 7 Daily Summary reported that results of samples EPA took on December 4 and 6 for a series of isocyanate compounds (hexamethylene diisocyanate, bisphenyl isocyanate and toluene-2,4-diisocyanate) in and around ground zero were non-detect. Further analysis shows that EPA did detect low levels of toluene-2,4-diisocyanate were identified at or just below the detection limit. All levels were below the OSHA permissible exposure limits.